Abstract: A multiple ratio automatic transmission having a hydrokinetic torque converter in an automotive vehicle driveline wherein the torque converter has a controllable bypass clutch and wherein provision is made for changing the clutch capacity during a ratio change to reduce undesirable torque fluctuations in the driveline, thus improving shift quality while maintaining optimum hydrodynamic torque converter efficiency.

Abstract: A system and method for controlling the bypass clutch of an automatic transmission includes an electronic microprocessor, an electronic memory accessible to the microprocessor, solenoid-operated bypass valve, pressure actuated bypass clutche, a variable force solenoid-operated bypass valve, a torque converter bypass friction clutch, and control algorithms that produce output signals to control the state of the solenoid-operated valve. The vehicle speed at which the bypass clutch engages and disengages, according to a reference schedule, is compensated for loss of engine torque at conditions that differ from the conditions at which the reference schedule is defined. Vehicle speed is compensated for torque variation with reference to the ratio of current calculated engine torque divided by current engine output torque.

Abstract: A system and method for controlling gear ratio changes in an automatic transmission includes an electronic microprocessor, an electronic memory accessible to the microprocessor, solenoid-operated shift valves, pressure actuated friction clutches and brakes, a variable force solenoid-operated valve, a torque converter bypass friction clutch, and control algorithms that produce output signals to control the state of the solenoid-operated valves. The vehicle speed and engine speed at which upshifts and downshifts occur, according to a standard gear shift schedule, is compensated for loss of engine torque at conditions that differ from the conditions at which a reference shift schedule is defined. Vehicle speed is compensated for torque variation with reference to the ratio of current calculated engine torque divided by current engine output torque.

Abstract: An electrohydraulic control system for an automatic transmission includes planetary gearsets, clutch and brakes that control the condition of the gear components, hydraulically actuated solenoid control valves, electronic sensors connected to a microprocessor, a gear selector mechanism and an overdrive cancel switch. The extent to which a gear ratio change is completed, as represented by the ratio of the current operating gear ratio and the gear ratio associated with gear ratio at the completion of the gear shift, is used as a variable in algorithms executed by the microprocessor to schedule change in state of solenoid operated valve. The state determines the engaged and disengaged condition of friction elements that produce the gear shift.

Abstract: An electronically controlled multiply ratio transmission for an automotive vehicle powertrain having a hydrokinetic torque converter with a bypass clutch, solenoid operated shift valves under the control of an electronic microprocessor that receives signals from an output shaft speed sensor, an engine speed sensor, a driver controlled drive range selector position, an engine throttle position sensor, and other powertrain operating variables, the bypass clutch having a controlled slip characteristic.

Abstract: A system for scheduling gear ratio changes in an automatic transmission and controlling operation of a torque converter bypass clutch includes a microprocessor; electronic memory containing control algorithms, lookup tables, functions and constants; solenoid-operated shift valves, a variable force solenoid, friction clutches, brakes and sensors, and planetary gear units. A table of calibrated performance weighting factors (PWF) is used to alter reference schedules of gear ratio changes based on the extent to which high performance operation is desired rather than economy operation. The PWFs are used to adjust gear shift points based on inferences drawn from engine throttle position and time rate of change of throttle position. Hydraulic pressure supplied to the friction elements and the schedule of unlocked and modulated operation of the torque converter are adjusted from reference schedules and pressures on the basis of PWF values.

Abstract: An electrically controlled multiple ratio transmission for an automotive vehicle powertrain having a hydrokinetic torque converter with a bypass clutch, solenoid operated shift valves under the control of an electronic microprocessor that receives signals from an output shaft speed sensor, an engine speed sensor, a driver controlled drive range selector position, an engine throttle position sensor, and other powertrain operating variables, the solenoid shift valves forming a part of a simplified control valve circuit having a minimum number of shift valve elements and simplified circuit pressure modifier elements for effecting optimum pressures in fluid pressure operated servos for the transmission clutches and brakes during ratio changes, the bypass clutch having a controlled slip characteristic.

Abstract: A multiple ratio automatic transmission having a hydrokinetic torque converter in an automotive vehicle driveline wherein the torque converter has a controllable bypass clutch and wherein provision is made for changing the clutch capacity during a ratio change to reduce undesirable torque fluctuations in the driveline, thus improving shift quality while maintaining optimum hydrodynamic torque converter efficiency.

Abstract: An electronic control system for scheduling gearshifts in an automatic transmission includes storing in electronic memory accessible to a microprocessor, functions relating vehicle speed to throttle position, one function being related to each upshift and downshift. Gearshifts are made by probing computer memory with current values for throttle position and vehicle speed, and determining on the basis of the stored shift schedule whether an upshift or downshift is required. Upshift points are determined also on the basis of an empirically determined function relating throttle position and vehicle acceleration immediately before an upshift. Shift control logic commands an upshift on the basis of a predetermined shift schedule, provided minimum vehicle acceleration-engine throttle position criteria are satisfied.

Abstract: An electronic control system for scheduling gearshifts in a four speed automatic transmission includes storing in electronic memory accessible to a microprocessor, six functions relating vehicle speed to throttle position, one function being related to each upshift and downshift. Gearshifts are made by probing computer memory with current values for throttle position and vehicle speed, and determining on the basis of the stored shift schedule whether an upshift of downshift is required. Upshift points are determined also on the basis of the maximum engine speed when a wide open throttle condition is detected. Electronic memory continually accessible to the microprocessor is updated with new calculated values of the ratio NOV divided by base NOV. Vehicle speed from a stored schedule of gearshift values is corrected with the calculated ratio to account for changes in the driveline components from their condition when originally installed and differences from a calculated base NOV value.

Abstract: An electronic control system for operating a torque converter clutch during a transmission gearshift includes a vehicle speed sensor and engine speed sensor, a hydrodynamic torque converter located between the engine and the transmission, a solenoid-operated hydraulic valve, which engages and disengages the torque converter clutch in accordance with the energized and deenergized state of the solenoid in accordance with the logic of the control system. The converter clutch is locked while operating in the original gear ratio, then unlocks during the gearshift, and relocks after the upshift is completed. The speed ratio of the torque converter is rapidly determined in terms of the number of clock ticks occurring between pulses whose frequency is proportional to engine speed. The current speed ratio is determined during interrupts occurring at short intervals during a background pass.

Abstract: An electronic control system for scheduling gearshifts in a four speed automatic transmission includes storing in electronic memory accessible to a microprocessor, six functions relating vehicle speed to throttle position, one function being related to each upshift and downshift. Gearshifts are made by probing computer memory with current values for throttle position and vehicle speed, and determining on the basis of the stored shift schedule whether an upshift or downshift is required. Upshift points are determined also on the basis of the maximum engine speed when a wide open throttle condition is detected. Ambient barometric pressure alters the vehicle speed and engine speed attained at high altitude in comparison to those speeds that result for the same throttle position at sea level.

Abstract: A hybrid hydraulic and electronic control valve system for an automatic, multiple-speed motor vehicle transmission having a torque converter with a lockup clutch and change-speed gearing adapted for four forward ratios and one reverse ratio, a converter lockup clutch control valve in conjunction with a lockup clutch shift valve adapted to control the lockup clutch and an electronic control module for superseding the action of the lockup clutch shift valve.

Abstract: A pneumatic throttle valve actuator for an automatic power transmission mechanism for use with a supercharged or turbocharged internal combustion engine wherein the relationship between manifold pressure and actuator force is changed when the engine manifold pressure changes from a positive pressure to a negative pressure or vice-versa. A correct shift point signal and a correct pressure regulator output thus are maintained regardless of whether the turbocharger or supercharger is active or inactive.

Abstract: A vacuum pressure regulator for an automatic transmission for use with an internal combustion engine having an air compressor on the intake side of the engine intake manifold whereby the signal made available by the regulator for the automatic transmission regulator is varied to provide transmission torque capacity proportional to engine torque throughout all engine operating modes regardless of whether the compressor is operating.